69MyWay

iTrader: (2)

I just picked up a long block to use some parts off it. It says both 4.8 & 5.3 on the block and has 862 heads. How do I know which one it is?

53bowtie

iTrader: (6)

you dont from the block....the only difference between the two is the stroke and rods.....the 4.8 has a shorter stroke and longer rods than the 5.3 (5.3, 5.7, 6.0 have 3.622" stroke and 6.098" rods) but both bores are exactly the same (3.779")....a 4.8 block is a 5.3 block, it just depends on the crank you put in it.....oh, also a 4.8 has flat top pistons and the 5.3 has dish pistons from the factory....

69MyWay

iTrader: (2)

Just to confirm...if I pull the head and it has a dish piston it is a 5.3 otherwise it is a 4.8???

Thanks!

53bowtie

iTrader: (6)

yes....i just edited the above post to give you stroke numbers on the 5.3 if you have any way to measure....other wise dish = 5.3 flat top = 4.8

69MyWay

iTrader: (2)

Hey Thomas...doesn't the 5.3 and 5.7 share the same crank?

I'm going to yank a head off this engine and take a look. Got it for free, so I am sure it is going to be a 4.8. However, I needed all the covers and hardware to put a bare 5.7 block together...so it won't be a total loss if it is a 4.8.

53bowtie

iTrader: (6)

5.3, 5.7, 6.0 all have same crank and rods just different bore sizes.....4.8=5.7 if you bore 4.8 block to 5.7 bore(3.9" i think) put a 5.3 (or 5.7,6.0) crank and 5.3 (or 5.7,6.0) rods in it......wola!!! iron block ls1 for cheaper than youll probably find one anywhere....plus its an iron block so turn up the boost!!!

53bowtie

iTrader: (6)

this is actually the setup i am goin to do im my truck this summer except i am not gonna run boost so i am gonna use my stock 5.3 heads and have them ported and milled .010 and i should have around 10.9:1 to 11.0:1 compression ratio....stock ls1 i believe is around 10.1:1....if your doing boost i would stay lower say in the 9.X:1 range...

69MyWay

iTrader: (2)

Just yanked the head and cleaned up this piston for a photo.

Looks like I got lucky.

69MyWay

iTrader: (2)

BTW - this means I have enough parts (less pistons) to assemble my bare block LS1, and I don't have to mess with the 98 LS1 that has a cracked bell housing mount from a collision.

Very cool!

53bowtie

iTrader: (6)

yep, you can reuse your 5.3L crank and connecting rods and the block if you have it bored....and if your not going to run fi you can reuse the 5.3 heads if you have them (if your going to run boost i would go with something like the 6.0 317 heads to give you a bigger cc and lower compression).....good luck with your build.....

69MyWay

iTrader: (2)

Man...you made my day! I actually have a spare bare LS1 aluminum 5.7, but didn't have a crank - however, it got some moisture on it and there is surface rust on the cylinders and I don't know if it is too much for a hone, or if it has to be punched. If it has to be punched - I have to get pistons anyway.

I may also just sell all this stuff as I picked up a crate LS2 last week and that will be going in the car now.

53bowtie

iTrader: (6)

thats cool, that ls2 will be badass....got a friend puttin that and a t56 in a 69 camaro....thing oughta fly........keep me posted on how it turns out.....by the way if you are gonna sell that block let me know...if i can get it at a reasonable price it may be worth it so i dont have as much machine work to do on my 5.3....thanks.

69MyWay

iTrader: (2)

I'll post it up here for sure if I let it roll.

Thanks!

joshua022

iTrader: (12)

Do you know how much of a dish the 5.3 pistons have is it 2cc? or what?? Tryin to calculate my buddies CR but don't know the dish size.